ok, so i'm not really knowing how to go about this problem. we're studying L'Hospital's Rule, so i know that's part of it. i guess i'm just uncertain how to handle the secant. anyway, here's the problem... lim (sec7x)(cos3x) as x tends to the negative side of pi/2. i know the limit is equal to positive infinity, but i'm not sure how to determine that from the equation. i suppose what it comes down to is how do you derive it? both parts require the chain rule, right? if so, does that mean that sec7x goes to 7(sec7xtan7x), and cos goes to 3(-sin3x)? any help would be appreciated.